Validator.prototype.checkDiscount = function(controlId, msg){
    var obj = document.forms[this.formName].elements[controlId];
	
    if ( Utils.trim(obj.value) == '' || 
	     !Utils.isNumber(obj.value) || 
		 (obj.value<=0 || obj.value>1))
    {
      this.addErrorMsg(msg);
    }
}

